Technical Field
The present invention relates to a system and method for classifying an Internet Protocol address, that is particularly useful for determining if the address corresponds to a server of a server farm.
Description of the Related Art
In a typical networked computing environment, a user may have a computer which connects via a local network (e.g. LAN or WAN) and a local network server to the Internet. In some environments, a proxy server (which may be coincident with the local network server) intercepts and interprets commands being transmitted between the Internet and a client, e.g. an e-mail client or MUA (Mail User Agent) running on a user's computer. The proxy server may monitor the Internet Protocol (IP) addresses being accessed by the client for the purposes of, for example: security filtering; or providing the client with access to files in a local cache rather than on an external server (i.e. a server accessible only via a network such as the Internet).
Many large service providers have a farm of external servers providing a given service, which although only a single server name is published, might have addresses as follows:
Server nameIP addresspop1.mailsp.com11.11.11.11pop2.mailsp.com11.11.11.12pop3.mailsp.com11.11.11.13pop4.mailsp.com11.11.11.14
When attempting to communicate with a server in a server farm, a client will start with only the published server name, e.g. ‘pop.mailsp.com’. This server name is resolved by the Domain Name Service (DNS) into one of the IP addresses in the server farm. A proxy server monitoring the IP addresses being accessed by the client may not recognize the particular IP address as belonging to a server farm; for example, the proxy server may not recognize that an IP address corresponds to an external email server if the external email server is part of a server farm, and therefore has multiple potential IP addresses. If the proxy server does not recognize the IP address, it may fail to function desirably: for example, a proxy server may fail to realize the IP address corresponds to a particular email server or perform access restriction.
It is desired to address the above, or at least provide a useful alternative.